1. Field of the Invention
The present invention relates in general to a device for providing a reference scale in photographic images that can be remotely projected into the field of view of a camera to facilitate size measurements of objects or features that are in the photograph
2. Description of the Background Art
Scaling devices, such as rulers, have long been used in photographs to provide a visual indication of the scale of other objects in the photograph. However, there are many situations where providing a scale reference in the photograph is overly difficult, if not impossible. As an example, NASA's Space Shuttle is often exposed to severe weather while on the launch pad at Kennedy Space Center during the many days leading up to a launch On at least one occasion, the Space Shuttle's External Tank (ET) suffered damage during a hailstorm that had to be examined to determine whether repairs were necessary. In this regard, it was necessary to determine the size of the hail damage sites on the ET's external foam because if the sites exceeded a certain size, they would have to be repaired. Actual examination of the ET's external foam would be difficult, time consuming, costly and dangerous given the inaccessibility resulting from the height, size and position of the ET while the Space Shuttle is on the launch pad. While the NASA operations personnel were able to measure the size of the hail damage sites in locations where access was possible, they had no way to do this along the large open expanse of the tank. Telephoto lenses might be used to zoom in and see the damage clearly, however, a viewer could not determine the scale of the damage because there would be no reference object in the image. This situation has therefore created a need for a technique that enables a scaling reference to be incorporated in a photograph of an object that is not readily accessible, thus precluding the actual physical placement of a scaling reference on or near the object.